RE: Tomcat cluster tuning
Sorry can't give a recommendation. We had different results even for (nearly) the same software for different sites. For one site the IBM JDK worked best, for the other Sun's. Any given result may be wothless with the next version of either jdk. (Even with just changes in the minor revision) You have to test that - in your environment - with your application - with the expected behaviour of the users Even small changes in one of these setting can change the result which jdk is better for you. (At least that's our experience) -Original Message- From: Cristopher Daniluk [mailto:[EMAIL PROTECTED] Sent: Thursday, September 11, 2003 7:04 PM To: 'Tomcat Users List' Subject: RE: Tomcat cluster tuning Are there any recommendations for what JVM would work best? We're not doing anything fancy, so presumably any VM that works well with tomcat would work well for us. Are there any sites that talk about the different JVM tuning options that affect Tomcat? I haven't seen that many. - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
Tomcat cluster tuning
We are runing a cluster of 3 apache servers and 2 tomcat servers connected via AJP w/Oracle on backend. The cluster has been performing very well but we've had a recent load spike that's causing the tomcat servers to start swapping pretty hardcore despite JVM limitations. What is the -Xmx option limiting? Threads? Defined services? Instances of Tomcat? I would've thought that it would limit the entire tomcat instance, but we have been far exceeding the 768mb limit we set. We're connecting to Oracle on the back end via the JDBC thin client. When the site starts swapping, performance on Oracle queries goes exponentially downhill. A non-db page takes about 1 second to load before swapping, vs 5 seconds to load when its swapping. On the other hand, a db intensive page takes about 5 seconds to load normally, vs about 40-50 seconds when it begins to swap. That number begins to crawl quickly up until it exceeds the 5 minute max execution time and Tomcat cuts the request off. The servers are basically identically configured P1.8ghz machines with 1gb ram each. The connector line from server.xml is: Connector className=org.apache.coyote.tomcat4.CoyoteConnector port=8009 minProcessors=5 maxProcessors=100 enableLookups=true redirectPort=8443 acceptCount=100 debug=0 connectionTimeout=-1 protocolHandlerClassName=org.apache.jk.server.JkCoyoteHandler / And we're running Apache 2.0.47 w/mod_jk1 and AJP1.3. the workers.properties is set to nonweighted balancing. Are there any options to tune tomcat to reduce memory footpritn and to let it queue more? We were initially running more maxProcessors but I turned it down hoping to alleviate the congestion. Tried turning it up thinking maybe the accept queue was the problem too, but that made it worse. Thanks, Cris - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
RE: Tomcat cluster tuning
mx is limiting the heap of a java process. In other words: It limits the total heap for one tomcat instance. The total memory can be much higher: - stacksize per thread Some vm's let you set these values (-Xss). If you have some hundred of threads that can make up some memory. - static memory (like string constants, the code, ...) That pretty much defined at compile time. - and may be further sorts of memories that depend on the vendor and version of the jdk. Regarding your config: You can try to play with the combination of maxProcessors connectionTimeout acceptCount I'm not shure how the accepted but not processed request are handled (wether they are queued in one thread, or if each has it's own thread) There isn't much more you can change in tomcat. The best recommendation I have is to find out where the memory comes from and either to cure the cause or find out that you have to live with that memory usage and spend more memory. -Original Message- From: Cristopher Daniluk [mailto:[EMAIL PROTECTED] Sent: Thursday, September 11, 2003 5:33 PM To: [EMAIL PROTECTED] Subject: Tomcat cluster tuning What is the -Xmx option limiting? Threads? Defined services? Instances of Tomcat? I would've thought that it would limit the entire tomcat instance, but we have been far exceeding the 768mb limit we set. Connector className=org.apache.coyote.tomcat4.CoyoteConnector port=8009 minProcessors=5 maxProcessors=100 enableLookups=true redirectPort=8443 acceptCount=100 debug=0 connectionTimeout=-1 protocolHandlerClassName=org.apache.jk.server.JkCoyoteHandler / - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
RE: Tomcat cluster tuning
Are there any recommendations for what JVM would work best? We're not doing anything fancy, so presumably any VM that works well with tomcat would work well for us. Are there any sites that talk about the different JVM tuning options that affect Tomcat? I haven't seen that many. -Original Message- From: Ralph Einfeldt [mailto:[EMAIL PROTECTED] Sent: Thursday, September 11, 2003 12:46 PM To: Tomcat Users List Subject: RE: Tomcat cluster tuning mx is limiting the heap of a java process. In other words: It limits the total heap for one tomcat instance. The total memory can be much higher: - stacksize per thread Some vm's let you set these values (-Xss). If you have some hundred of threads that can make up some memory. - static memory (like string constants, the code, ...) That pretty much defined at compile time. - and may be further sorts of memories that depend on the vendor and version of the jdk. Regarding your config: You can try to play with the combination of maxProcessors connectionTimeout acceptCount I'm not shure how the accepted but not processed request are handled (wether they are queued in one thread, or if each has it's own thread) There isn't much more you can change in tomcat. The best recommendation I have is to find out where the memory comes from and either to cure the cause or find out that you have to live with that memory usage and spend more memory. -Original Message- From: Cristopher Daniluk [mailto:[EMAIL PROTECTED] Sent: Thursday, September 11, 2003 5:33 PM To: [EMAIL PROTECTED] Subject: Tomcat cluster tuning What is the -Xmx option limiting? Threads? Defined services? Instances of Tomcat? I would've thought that it would limit the entire tomcat instance, but we have been far exceeding the 768mb limit we set. Connector className=org.apache.coyote.tomcat4.CoyoteConnector port=8009 minProcessors=5 maxProcessors=100 enableLookups=true redirectPort=8443 acceptCount=100 debug=0 connectionTimeout=-1 protocolHandlerClassName=org.apache.jk.server.JkCoyoteHandler / - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED] - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
